These experiments were carried out during two successive summer seasons of 2013 and 2014 on Jerusalem artichoke cv. Feusa. The plants were grown at Kaha Vegetables Res. Farm, Hort. Res. Inst., Agric. Res. Centre, under clay loam soil with using surface irrigation system, to study the effect of boron , copper and humic acid on vegetative growth, yield and its components , chemical constituents and storability of Jerusalem artichoke tubers. The experiment including 9 treatments ( foliar spray with 70 and 140 ppm boron, 50 and 100 ppm copper, 0.5 and 1 g/l humic acid as foliar application and 0.5 and 1 g/l humic acid as soil application beside of the control treatment ( spraying with water). The experiment was arranged in a randomized complete block design with three replicates.
The obtained results showed that the highest value of plant height was recorded by the plants which for sprayed with 50 or 100 ppm copper . While the plants which sprayed with 140 ppm boron gave the highest number of main stems per plant. Application of humic acid 1 g/l as soil application increased dry weight of foliage, number of tubers, yield per plant and total yield per feddan. Moreover, sprayed plants with 140 ppm boron treated plants with 1 g/l humic acid as soil application produced more average tuber weight than the other tested treatments. Chemical composition (N, P, K, Total carbohydrates and inulin contents) of Jerusalem artichoke was significantly affected with application all treatments than control treatment.The results also confirmed that weight loss and decay percentage in Jerusalem artichoke tubers increased with prolongation of storage period.
In addition, the plants, which sprayed with copper or boron in both concentrations, gave the lowest values in weight loss and decay percentage in Jerusalem artichoke tubers during the storage period.
Conclusively, from the obtained data in this study, it can be recommended by using humic acid at soil for improve growth, number of tubers, yield per plant and total yield. On the other hand, foliar application of boron on Jerusalem artichoke plants increased average tuber weight. Also, foliar spray with copper or boron helps to storage the tubers and low rate of weight loss and decay.